Difference between revisions of "Time-of-Flight/Start-Counter/Target Meeting, November 13, 2009"
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# Target Status | # Target Status | ||
# [[Time-of-Flight/Start-Counter Action Items|Action Items]] | # [[Time-of-Flight/Start-Counter Action Items|Action Items]] | ||
| + | |||
| + | =Minutes= | ||
| + | |||
| + | sasha | ||
| + | rory | ||
| + | werner | ||
| + | aram, sascha, david, mark | ||
| + | |||
| + | 50 of real, now few percent cross-talk, not sure what solution was, using 4 ns delay cable now, checked cables | ||
| + | timing measurements | ||
| + | time difference, resolution 100 ps, caen vme got about 124 ps | ||
| + | cosmic test ortec cf 8000, going on now, claim 250 ps time walk, philips 75, caen 100? ps | ||
| + | no time walk corrections thus far | ||
| + | somov, rate considerations might argue for leading edge | ||
| + | 30 MHz and above in spec of most discriminators | ||
| + | david: with time walk correction, it may not make a difference, leading edge or constant fraction | ||
| + | bar is 2.5 meters long, current numbers are for the middle of the bar | ||
| + | some of coincidences may be due to cross talk | ||
| + | still hoping to get a flash from jlab | ||
| + | rumor of photonis-clone company, | ||
| + | 2x10^6 gain can be obtained from Hamamatsu, will try to get some | ||
| + | Sasha split of signal? No plan yet. | ||
| + | |||
| + | werner | ||
| + | working on light output, found | ||
| + | |||
| + | rory | ||
| + | at jlab yesterday, discussion about target | ||
| + | organizanal | ||
| + | remains a jlab project, cryogenic capability | ||
| + | umass play role in organization and oversight | ||
| + | perhaps slow controls | ||
| + | a lot of stuff to be developed for control software | ||
| + | solid targets, interest in gluex, especially for calibration | ||
| + | physically remove cryotarget, put in solid target ladder | ||
| + | in situ, downstream not attractive for gluex because of extra material in beamline (from discussion in spring) | ||
| + | 8 hour change-over time from cryo to solid | ||
| + | umass would build the ladder for solid target | ||
| + | roster of target materials to be decided, input from gluex for calibration purposes | ||
| + | if cryotarget comes out, there is room for planning | ||
| + | perhaps a target wheel | ||
| + | perhaps motion in z | ||
| + | single foil at detector center | ||
| + | question from Rory: how much depends on absolute cross sections, what is level? | ||
| + | primex shoots for 0.1% | ||
| + | writing an mou target mentioned | ||
| + | David: calibration channels for solid target? | ||
| + | Rory: calibration target for tracking | ||
| + | target group at jlab: they will make the target, cryogenic system, target cells will be made in a Christo-like fashion | ||
| + | refrigerator: buy stand-alone, decoupled from the magnet. not that expensive. | ||
| + | diameter: 2cm? | ||
| + | for primex might be fatter, want photons exiting downstream cell wall | ||
| + | may have more than one cell | ||
| + | aram fleeing to canada to avoid the draft | ||
| + | hall d target: postdoc to be hired at umass | ||
| + | |||
| + | discussion with Sasha read into minutes by Mark | ||
Revision as of 21:38, 14 November 2009
Location, Time
Friday, November 13, 2009
2:00 pm EDT
JLab: CEBAF Center, Room F326/7
ESNet: 8542553
EVO: direct meeting link
Conference Group: 800-377-8846, participant code: 77438230
Slides: talks can be deposited in the directory /group/halld/www/halldweb1/html/talks/2009-11 on the JLab CUE (you have to be a member of the "halld" group). This directory is accessible from the web at https://halldweb1.jlab.org/talks/2009-11/ .
Agenda
- Minutes from the last meeting
- Time-of-Flight Status
- Start Counter Status
- Target Status
- Action Items
Minutes
sasha rory werner aram, sascha, david, mark
50 of real, now few percent cross-talk, not sure what solution was, using 4 ns delay cable now, checked cables timing measurements time difference, resolution 100 ps, caen vme got about 124 ps cosmic test ortec cf 8000, going on now, claim 250 ps time walk, philips 75, caen 100? ps no time walk corrections thus far somov, rate considerations might argue for leading edge 30 MHz and above in spec of most discriminators david: with time walk correction, it may not make a difference, leading edge or constant fraction bar is 2.5 meters long, current numbers are for the middle of the bar some of coincidences may be due to cross talk still hoping to get a flash from jlab rumor of photonis-clone company, 2x10^6 gain can be obtained from Hamamatsu, will try to get some Sasha split of signal? No plan yet.
werner working on light output, found
rory at jlab yesterday, discussion about target organizanal remains a jlab project, cryogenic capability umass play role in organization and oversight perhaps slow controls a lot of stuff to be developed for control software solid targets, interest in gluex, especially for calibration physically remove cryotarget, put in solid target ladder in situ, downstream not attractive for gluex because of extra material in beamline (from discussion in spring) 8 hour change-over time from cryo to solid umass would build the ladder for solid target roster of target materials to be decided, input from gluex for calibration purposes if cryotarget comes out, there is room for planning perhaps a target wheel perhaps motion in z single foil at detector center question from Rory: how much depends on absolute cross sections, what is level? primex shoots for 0.1% writing an mou target mentioned David: calibration channels for solid target? Rory: calibration target for tracking target group at jlab: they will make the target, cryogenic system, target cells will be made in a Christo-like fashion refrigerator: buy stand-alone, decoupled from the magnet. not that expensive. diameter: 2cm? for primex might be fatter, want photons exiting downstream cell wall may have more than one cell aram fleeing to canada to avoid the draft hall d target: postdoc to be hired at umass
discussion with Sasha read into minutes by Mark
